Supplementary Material for: Comparison of Stromal/Stem Cells Isolated from Human Omental and Subcutaneous Adipose Depots: Differentiation and Immunophenotypic Characterization

The emerging field of regenerative medicine has identified adipose tissue as an abundant source of stromal/stem cells for tissue engineering applications. Therefore, we have compared the differentiation and immunophenotypic features of adipose-derived stromal/stem cells (ASC) isolated from either omental or subcutaneous adipose depots.<b> </b>Human tissue samples were obtained from bariatric and plastic surgical practices at a university-affiliated teaching hospital and a private practice, respectively, with informed patient consent.<b> </b>Primary cultures of human ASC were isolated from adipose specimens within 24 h of surgery and culture expanded in vitro. The passaged ASC were induced to undergo adipogenic or osteogenic differentiation as assessed by histochemical methods or evaluated for surface antigen expression profiles by flow cytometry. ASC yields per unit weight of tissue were comparable between omental and subcutaneous depots. At passage 0, the immunophenotype of omental and subcutaneous ASC were not significantly different with the exception of CD105 and endoglin, a component of the transforming growth factor β receptor. The adipogenic differentiation of omental ASC was less robust than that of subcutaneous ASC based on in vitro histochemical and PCR assays. Although the yield and immunophenotype of ASC from omental adipose depots resembled that of subcutaneous ASC, omental ASC displayed significantly reduced adipogenic differentiation capacity following chemical induction. Further studies are necessary to evaluate and optimize the differentiation function of omental ASC in vitro and in vivo. Pending such analyses, omental ASC should not be used interchangeably with subcutaneous ASC for regenerative medical applications.

新兴的再生医学领域已将脂肪组织认定为组织工程应用中基质/干细胞（stromal/stem cells）的丰富来源。因此本研究对比了从网膜脂肪垫（omental adipose depots）与皮下脂肪垫（subcutaneous adipose depots）分离得到的脂肪来源基质/干细胞（adipose-derived stromal/stem cells, ASC）的分化特性与免疫表型特征。
人体组织样本分别取自大学附属教学医院的肥胖外科与整形外科临床业务，以及一家私立医疗机构，所有受试者均已签署知情同意书。
术后24小时内从脂肪标本中分离原代人ASC，并进行体外培养扩增。将传代后的ASC诱导其向成脂或成骨细胞分化，通过组织化学方法（histochemical methods）评估分化效果，或通过流式细胞术（flow cytometry）检测其表面抗原表达谱。
每单位组织重量的ASC收获量，在网膜与皮下脂肪垫之间无显著差异。第0代时，网膜与皮下ASC的免疫表型除CD105与内皮糖蛋白（endoglin，转化生长因子β受体（transforming growth factor β receptor）的组成成分）外，其余指标均无显著差异。
基于体外组织化学与聚合酶链式反应（Polymerase Chain Reaction, PCR）检测结果，网膜ASC的成脂分化能力弱于皮下ASC。
尽管网膜来源的ASC收获量与免疫表型与皮下ASC相近，但经化学诱导后，网膜ASC的成脂分化能力显著降低。未来需开展进一步研究，以在体内外评估并优化网膜ASC的分化功能。
在完成此类相关分析之前，再生医学应用中不应将网膜ASC与皮下ASC互换使用。